partitioning - Convert Hybrid GPT/MBR to pure GPT partition scheme

I was wondering how to safely convert a Hybrid GPT/MBR to a pure GPT partition scheme? (Without Reformatting)

The reason why I ask is, I currently triple-boot with Ubuntu 16.04 LTS, Windows 10 and Mac OSX Lion.

Originally I needed to format my drive with a Hybrid partition scheme to install Windows 7 but I have since upgraded to Windows 10.

I know now that Windows 10 supports booting from GPT partitions and I would like to covert everything to a pure GPT partition scheme without reformatting.

If I can do this, I would be able to reformat my HFS+ partition to an APFS partition and install High Sierra.

So the questions are:

1. How do I convert my Hybrid MBR to a pure GPT?


2. Will it break booting into any of my OSes if I do? (Windows 10, Linux, MacOSX)

Here is my gdisk output:

GPT fdisk (gdisk) version 1.0.1

Partition table scan:
  MBR: hybrid
  BSD: not present
  APM: not present
  GPT: present


Found valid GPT with hybrid MBR; using GPT.

Command (? for help): p
Disk /dev/sda: 3907029168 sectors, 1.8 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): CBC86EEB-C878-4C46-9963-120433EB0BED
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 3907029134
Partitions will be aligned on 8-sector boundaries
Total free space is 269477 sectors (131.6 MiB)


Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF02  EFI System Partition
   2          409640       293378391   139.7 GiB   AF00  Mac OSX
   3       293642240       684265471   186.3 GiB   0700  WINDOWS 7
   4       684265472      1075085311   186.4 GiB   0700  LINUX
   5      1075085865      1087375589   5.9 GiB     8200  
   6      1087375590      3907024064   1.3 TiB     0700